Waterproof cartridging for explosives



June 28, 1932. R. HILL v WATERPROOF CARTRIDGING FOR EXPLOSIVES Filed March 26, 1930 r4.9, rfc.

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' Patented June 28, 1932` UNITED y STATES PATENT; OFFICE BY HILL, F WILMINGTON, DELAWARE, ASSIGNOR T0 ATLAS POWDER COM- PAN'I, 0F WILMINGTON, DELAWARE, A CORPORATIGN 0F DELAWARE WATERPROOF CABTRIDGING FOR EXPLOSIV ES This invention relates to a means of cartridging explosives, so that they will be thoroughly protected against 'considerable water pressures for desirable lengths of time.

In blasting under wet conditions, in the past, the consideration has had to be whether a given explosive will be sufiiciently water resistant, rather than whetlfer it is'the most eiiicient, or the most economical. Accordingly, for instance, there are frequent cases where expensive gelatin dynamites are used for work which definitely demands black powder, o r low density ammonium nitrate dynamites.

For several years I have been experimenting with numerous types of assemblies with the object of securing a construction which would eiiiciently resist the entrance of water or moisture, even in the presence of considerable pressures. I have extensive records of negative results, lbut met with a high degree of success with the constructions hereinafter described. In the solution of this problem, I

was confronted by the necessity for reasonable economy in materials, manufacturing assembly and use as well as in the primary requisite of water resistance.' Many ways may be resorted to for carrying out the invention, but for purposes of explanation, I 1 ployed in wherein,

Fig. 1 is a vertical sectional view illustrating an end closure for one form of container, and

t Fig. 2 is a fragmentary sectional view modithe accompanying drawing,

upon an enlarged scale, illustrating a fied form lof end closure. A

Broadly stated, the invention4 resides in providing a tubular container of paper, which mayy be built up in any of the many ways common in the forming of paper cans, j mailing tubes, and the like. l The ody of the container should consist of, at least, two plies of material ofthe nature of heavy paper, cardboard, chiplooard or pressed pulp. -In the accompanying drawing, I have shown a form of construction wherein the two plies 5 and Gare spirally wound 'in opposite directions, and 1n overlapping relation,.but any have shown constructions which may be emway offorming the body of the container may bev resorted to, as long as it lprovides a structure of such weight and strength as to stand up under service conditions. Each ply of the material is impregnated with a suitable waterproofing composition, such as parailin, and the plies are further waterproofed and sealed together with tar, asphaltum, and the like. The character of the material used and the number of lies are determined by the water pressure w ich the assembly must stand. As before stated, tubes of the general nature described have been used as the basis for certain forms of paper cans. However, I have found no form of paper can end closure which is, at the same time, water tight, resistant to water pressure, safe to use with explosives, and economically advantageous. It was in the provision of a suitable water tight closure, for a paper structure of this character, thatI experienced the greatest diiiiculty in my experiments, which were prolific of many negative results, in connection therewith.

One form of suitable water tight end closure for an explosive cartridge of the character described, is illustrated in Fig. 1, where 7 designates a paper cap, shaped and dimensioned tofit upon the end of the tubular structure constituted by the plies 5 and 6. This `cap may be reinforced, if desired, by an internal reinforcing disc of metal, indicated at 8, and I may apply a heavy coating of wax, tar, asphaltum, paraffin, or the like, indicated at 9, to the interior of the cap structure, so that when the cap is forced down upon the tube, this material will tend to make a water tight seal at the juncture of the end of the tube, with the cap. However, this sealing material 9, and the reinforcing disc 8, may be omitted, and the paper cap may be permitted to contact directly with the end of the tube. In either case, the assembly is dipped, 'after the capvhas been placed in position, in a material which lis highly adhesive, water re- 95 sistant, and will not become brittle when subjected to the climatic conditions which the explosive cartridges may encounter. As the dip, I may yuse tar, asphaltum, wax, nitrocellulose solutions, or any other suitable 100 aoteristics specifi water roo com osition havin the char- P fing Around thig dip a I fasten a ca 10, which maybe made of paperJ but is, pre erably, made ofrubberized sheeting, this iexible cap being tied into the dipping material, and, preferably, before the s etting of the latter, the tying strands being 1ndioated at 11. If desired, I may leave the ends of these tying strandsof such length as to constitute lowering cords 12, by which the .cartridges may be lowered gently ,into bore holes, or equivalent lowering cords may be seouredto the cartridges in any desired Way.

In the form of the invention illustrated inl Fig. 2, the tubular cartridge is indicated at 12a, and a metallic cap is indicated at 13.

'When a metallic cap isemployed,

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Y, prefer-r ably use zinc or lead, because they are nonking, an consequently, are safe when used in connection w1th explosives. IWhen metal caps are used, it is not always necessary to resort to the dipping, wrapping and tyin operations, though these may be employe in conjunction with the metal caps, in the manner illustrated with 'respect to the paper caps, of Fig. 1. However, I have obtained good results by heavily painting or coating L the interior of the metal caps with tar, asphaltum, orwax, indicated at 14, in Fig. 2,

' ners, and I may L charge,

vIn the case of soft metal caps,

and covering the juncture of ca and tube with a water resistant, and adheslve tape 15. In my investigations, I have found that my tubular bodies may have ample resistance against a given water pressure, and yet collapse slightly at the ends. This does no harm in the dipping, wrapping and tying method. enough strength is provided to prevent such collapse, to a large extent. Even if the 'metal does collapse to some extent, it is resistant to water leakage, unless there is an actual fracture. However, if desired, Ifmay provide the metal caps with reinforcing beads about their corprovide reinforcing rings, as indicated at 16, or I may use reinforcing discs, like the disc 8. The complete assembly l is, preferably, dipped in some waterproofing medium, such as paraffin, because this tends to reinforce the othery Waterproofing steps.

4llVhen it is reiected that an unprotected spot the size of a pin point may undo all waterproofing effects, and ruin anI explosive and bring about expensive misfires, the `importance of adequate and complete Waterproofing will be apparent. In a rigid or semi-rigid assembly of the nature of that herein described, there is always the possibility that lsome rupturing may occur if the cartridges are dropped into deep bore holes, unless the cartrid e structure is very strong. Therefore, I, preerably, supply a lowering cord attached to each cartridge rather than to incur the expense of extra strongassembly.

It is to be understood that the invention includes Within its purview whatever changes fairly come within either the terms or the spirit of the appended claims. s

Having described my invention, what I claim is:

1. In'a blasting cartridge, the combination with apreformed paper body,'of sufficient rigidity to maintain its form in the absence of the explosive, a cap constructed to fit snugly upon and close the end thereof, a'd'ipping of waterproof and adhesive material which extends to a point beyond the inner end of the cap, proof material outside of said dipping which encloses said cap and is embedded in the dipping material at a point inwardly of the inner edge of said cap. f

2. In a blasting Cartridge, the combination with a preformed paper body, of suiiicient rigidity a cap constructed to it snugly'upon and close the end thereof, a dipilng of waterproof and adhesive material w 'ch extends to a point beyond the inner end of the cap, a fiexible wrapping of waterproof material outside of said dipping, and tying means for said iiexible wrapping, inwardly of the inner end of the cap which forces said wrapping into the said adhesive material.

3. In a blasting cartridge,the combination with a preformed paper body, of suiicient rigidity to maintain its form in the absence of the explosive, a cap constructed to flt snug# ly upon and close the end thereof, a dip ing of waterproof and adhesive material w ich extends to a point beyond the inner end of the cap, and a reinforcing means within said cap, a webof rubberized sheeting enclosing said cap extending beyond the inner edge o the same to lie upon the paper body, a relatively thick coating of a waterproof dipping material upon said cap and a part of said body and means for forcing said sheeting into said dipping material.

4. In a blasting cartridge the combination with a tubular container of paper, of a ca adapted to lit snugly thereon, a body of sea ing material within the cap, waterproofing and adhesive material outside ofthe cap which extends to a point inwardly of the inner end of the cap, a wrapping of flexible waterproof material outside of said dipping material and means for constricting the inner portion of said wrapping.

5. Ina blasting cartridge, the combination with a tubular container of paper, of a cap adapted to fit snugly thereon, a body of sealing material within the ca a dipping of waterproong and adhesive material outside of the cap which extends to a point inwardly of the inner end ofthe cap, a wrapping of flexible waterproof material outside of said dipping material, and a tying cord for binding the inner end of the wrapping means.,

6. An explosive assembly comprising in veombinatlon a preformed paper body of su'fand a iexiblewrapping of watera dipping of to maintain its form in the` absence of the explosive,

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fcient rigidity to maintain its form in the absence of an explosive content, a cap adapted to fit snugly upon and close the end thereo, a dipping of waterproof and adhesive material which extends to a point beyond the inner end of the cap, a wrapping of flexible Waterproof material outside of said dipping material, and a tying cord for binding the inner end of the Wrapping, the terminal end of which is left free and long enough to constitute a lowering cord for the explosive assembly.

In testimony whereof I affix my VVsi ROY LINDEN ature. ILL. 

